1. Field of the Invention
The present invention relates to an apparatus and method for transferring (or moving) a Rights Object (RO) between devices in a Digital Rights Management (DRM), and more particularly, to an apparatus and method for transferring an RO for a digital content from one device to another device via a server.
2. Description of the Related Art
Digital contents may be acquired through every available routes, for example, by being downloaded from a website of a Content Issuer (CI) or received by mail (e.g., e-mail) or any media from other equipment. In order to use the digital contents, a Rights Object (RO) should be issued by a Rights issuer (RI). A technology related to this is referred to as a Digital Rights Management (DRM).
A DRM agent is generally a software or program installed in a device which uses the contents. Instead of CIs and RO providers, the DRM agent prevents illegal use and piracy of digital contents, and protects their copyrights.
Two types of ROs include a stateful RO and a non-stateful RO. The stateful RO is limited by constraints such as the number of usage times or a used time. Here, when reproducing (playing) a corresponding digital content, it is necessary to inspect and record how many rights have been used, the recorded information being called state information. Therefore, the state information is generally updated simultaneously when playing digital contents.
Typically, in order to use a certain digital content in the DRM System, a device user should directly have an RO for the content issued by an RI. Many methods by which a device accesses an RI to acquire an RO issued by the RI have been introduced.
However, a detailed method by which an authenticated device transfers (e.g., delivers, moves, etc.) all or part of its own RO directly issued by an RI to another device has not been proposed yet.